title: Comparison of radiosurgery treatment modalities based on complication and control probabilities.
abstract: OBJECTIVE
  The relative efficacy of Gamma Knife, Linac, and Proton treatment modalities for stereotactic radiosurgery (SRS) was investigated on the basis of normal tissue complication probability (NTCP) and tumor control probability (TCP), calculated for representative test cases.
  
  
  METHODS
  Five radiosurgery patient cases were selected to cover a range of treatment-planning situations from small spherical volumes to large irregular volumes. A target volume consisting of contours drawn on CT transverse slices was prepared for each case. Plans were developed using the three treatment modalities for each case, with the objective of encompassing the target as closely as possible with a prescription isodose line and minimizing dose to normal tissue, within the constraints of current clinical practice. Dose-volume histograms (DVH) were calculated for the target and for normal tissue, and these histograms were used to calculate NTCP and TCP values for each plan.
  
  
  CONCLUSIONS
  Differences in NTCP and TCP values were found to depend on treatment modality, size, shape, and location of the target, the amount of effort devoted to treatment planning, and the complexity of the plan.
authors.affiliation: Department of Radiation Oncology, University of California, San Francisco 94143-0226, USA. smith@radonc4.ucsf.edu
authors.forename: V
authors.initials: V
authors.lastname: Smith
authors.forename: L
authors.initials: L
authors.lastname: Verhey
authors.forename: C F
authors.initials: CF
authors.lastname: Serago
mesh_terms: D000465:Algorithms; D001932:Brain Neoplasms / Q000473:pathology / Q000601:surgery*; D006801:Humans; D011336:Probability; D016634:Radiosurgery / Q000009:adverse effects* / Q000379:methods*; D011879:Radiotherapy Dosage